Remove Indentation for a Single Paragraph

Question

Is there a way to remove the indentation at the beginning of a paragraph for a single paragraph. I know I could do

\setlength{\parindent}{0cm}
This is my paragraph.  Blah blah blah.
\setlength{\parindent}{default}

Where default is whatever the default indentation is for the document class I am using (part of the problem is that I don't know what this default value is). I feel as if there should be a better way to accomplish this than by the above method. I am looking for a solution of the form:

\noindent
This is my paragraph.  Blah blah blah.

Is there a way to do this, or will I have to resort to the former method? If I have to resort to the former method, what is the default indentation value for the amsart document class?

Answer 1

As the example below illustrates, \noindent suppresses paragraph indentation when used at the beginning of a paragraph. If used in the middle of a paragraph, it is ignored and does not suppress the paragraph indentation.

Also, you can always group things within a {} so that any settings within their are not in effect after the group. This saves you from having to store the old setting and restore it afterwards.

Notes:

• One can use \indent to produce a horizontal space equal to the width of the paragraph indentation.
• The [showframe] option was used with the geometry package to show the margins so that the indentation is clearly shown.

Code:

\documentclass{article}
\usepackage[showframe]{geometry}

\begin{document}
This is my paragraph 1 and is indented.  Blah blah blah.

\noindent
This is my paragraph 2 but is not indented since it was started with noindent.  Blah blah blah.

This is my paragraph 3 and is indented.  Blah blah blah.

{\setlength{\parindent}{0cm}
This is my paragraph 4 but is not indented since parindent was set to 0 within this group.  Blah blah blah.
}

This is my paragraph 5 and is indented since the above setlength was within a group.  Blah blah blah.
\end{document}